Various methods are known for separating or concentrating gas mixtures, in particular isotope mixtures.
In practice, to obtain concentrations of U 235 from a uranium isotope mixture, the principal method is the diffusion technique. The so-called gas-centrifuge technique and separating nozzle technique have also been used. In all three methods, because of the low separating effect or the low throughput, a large number of separating stages must be provided in cascade in order to achieve the necessary concentration. Furthermore these methods have disadvantageously high energy consumption and high investment costs.
Austrian patent No. 238 697 describes an apparatus for separating or concentrating gas mixtures. This apparatus comprises a disc rotating at high speed and having an annular supply or feed region for the mixture extending radially, this region communicating with at least one nozzle orifice extending radially of an annular nozzle and adjoining the nozzle orifice approximately in the plane of the nozzle orifice. The supply region comprises a delivery pipe for the heavy fraction of the mixture and on both sides of the nozzle orifice, delivery pipes for the light fraction of the mixture. However, in practice, this apparatus has not proved successful in isotope, particularly uranium isotope separation.